Percussion-tool.



J. THIELE.

. PERCUSSION TOOL. urmouxon FILED JAN. 7, 1911.

'NVENTOK .Jzbaflnes The /e bYius TTaRNEYs COLUMBIA I'LANOGRAPH co., WASHINGTON, I). c.

Patented Aug. 29, 1911.

1 %TATE% PATET FFlfiE.

JOHANNES TI-IIELE, OF FRIEDENAU, NEAR BERLIN, GERMANY, ASSIGNOR TO SIEMENS- SCI-IUGKEBT VZER-KE G. M. B. 11., OF BERLIN, GERMANY.

PERCUSSION-TOOL.

mower.

Specification of Letters Patent.

Patented Aug. 29, 1911.

Application filed January 7, 1911. Serial No. 601,411:

To all whom it may concern:

Be it known that I, JorrANNns THIELE, a subject of the German Emperor, and re siding at Friedenau, near Berlin, Germany, have invented certain new and useful Improvements in Percussion-Tools, of which the following is a specification.

My invention relates to percussion tools, in which a spring-pressed percussion member is periodically drawn backward and released by specially driven cams or the like.

The performance or capacity of working of such percussion tools is dependent on the pressure of the spring, presupposing that the number of blows and the stroke of the percussion member remain constant. The tension of the spring and with it the strength of the blows was regulated heretofore by screw -threaded sleeves, regulating levers or set-screws. But such regulation is unsuitable in many instances because work has to be interrupted and the regulation requires a certain time.

A. primary object of my invention is to remedy this defect. To this end, I make the tension of the spring dependent solely on the pressure which is exercised in the direction of the blow by the workman when he holds the tool in a normal manner.

One illustrative embodiment of my invention and a modification thereof are represented by way of example in the accompanying drawing, wherein Figure 1 is an elevation, partly in sect-ion, showing one form of an improved percussion drill, Fig. 1 shows two details thereof in elevation, and Fig. 2 is an elevation, partly in section, showing a modified form of drill.

Referring firstly to Figs. 1 and 1 the outer casing (a, which is generally held in the hand, and is consequently to be regarded as stationary, contains a socket or sleeve Z). This can be driven by means of its rod 6 projecting out of the casing, through the medium of a flexible shaft. by a motor. Within the socket b is the coil spring 0 which, on the one hand, abuts against the top end of the socket and, on the other hand, against the percussion member (Z. The latter is a fairly long pin provided above with the portion of a screw-thread (Z A corresponding portion of a screw-thread e, is provided on the bushing e which is axially displaceably connected with the socket Z).

The members 0 and (Z respectively provided with the portions of screw-thread c, and (Z are shown separately in Fig. 1

The bushing c abuts below against the stop f which is longitudinally displaceably, but not revolubly connected with the casing a. The parts of the tool are normally held together by the cap-screw g.

The two cam-like members (Z, and e, are not complete turns of a screw-thread buteach has a part cut away. When the socket Z) rotates in the direction of the arrow the member (Z, is pushed upward by the menr ber 6 and compresses the spring 0. lVhen the recesses in the screw-threads arrive opposite one another the percussion member (Z is suddenly released and driven by the spring 0 against the operative tool it which is guided longitudinally in the stop f.

The strength of the blows is regulated by driving the casing a forward in the direction of the blow. The cutter h then abuts against thematerial being worked, and the collar h, of the cutter abuts against the stop f, which consequently enters farther into the casing a, and by pushing the bushing 6 back compresses the spring 0. The stroke of the percussion member (Z, however, remains unchanged.

Referring to Fig. 2, in order to be able to use the tool with a certain tension of the spring without having constantly to press on the tool, the stop f is provided with teeth f, in which a catch i pivoted on the casing a engages. The adjustment of the stop f in the casing (11. and consequently the tension of the spring 0 and with it the performance of the tool can thus be maintained as desired within the given limits. Otherwise, this form of tool. operates in the same manner as that described with reference to Figs. 1 and l.

I claim 1. In a percussion tool, the combination, with a casing, a socket revoluble therein, a percussion member axially displaceable in the casing, a spring in the socket pressing the percussion member, and means opera tively connected with the socket for driving the percussion member against the action of the spring and releasing the same, of an operative tool, and a member operatively connected with the latter and slidable axially in the casing for adjusting the tension of said spring.

2. In a percussion drill, the combination, with a casing, a socket revoluble therein, a percussion member axially displaceable in the casing, a spring in the socket pressing the percussion member, and means operatively connected with the socket for driving the percussion member against the action of the spring and releasing the same, of a cutter, a stop slidable axially in the casing, a cutter movably carried by the stop, and means mounted on the casing for holding the stop.

3. In a percussion tool, the combination with a casing, a socket rotatable therein, a percussion member axially displaceable in the casing and having a spiral cam member at its upper end which is located in said socket, a spring in said socket bearing against said cam member, an abutment member in the lower end of said casing having freedom of axial movement therein and serving as a guide for the lower end of said percussion member, a sleeve surrounding said percussion member abutting at one end against said abutment and having its other end located in said socket to which it is splined, said sleeve having a spiral cam surface at the upper end which cooperates with the cam surface of said percussion member whereby said spring tends to hold said cam surface in engagement and whereby said sleeve drives said percussion member against the action of said spring when said socket is rotated, an operative tool in said abutment member cooperating with said percussion member and provided with a collar at the outside which seats against said abutment, whereby the forward pressure of said tool and said abutment tends to increase the tension of said spring.

4. In a percussion tool, the combination with a casing, a socket rotatable therein, apercussion member axially displaceable in the casing and having a spiral cam member at its upper end which is located in said socket, a spring in said socket bearing against said cam member, an abutment member in the lower end of said casing having freedom of axial movement therein and serving as a guide for the lower end of said percussion member, a sleeve surrounding said percussion member abutting at one end against said abutment and having-its other end located in said socket to which it is splined, said sleeve having a spiral cam surface at the upper end which cooperates with the cam surface of said percussion member whereby said spring tends to hold said cam surface in engagement and whereby said sleeve drives said percussion member against the action of said spring when said socket is rotated, an operative tool in said abutment member cooperating with said percussion member and provided with a collar at the outside which seats against said abutment, whereby the forward pressure of said tool and said abutment tends to increase the tension of said spring, and a ratchet on said abutment member and a pawl on said casing cooperating therewith, for holding said member in position to maintain a desired spring tension. 7

In testimony whereof I have signed my name to this specification in the presence of two witnesses.

J OHANNES THIELE. Witnesses:

WALDEMAR HAUPT, HENRY HASPER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, D. C. V 

